Convert all modeltests to use absolute imports, rather than relative ones.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@16975 bcc190cf-cafb-0310-a4f2-bffc1f526a37

tests/modeltests/field_subclassing/fields.py

@@ -2,6 +2,7 @@ from django.db import models
 from django.utils import simplejson as json
 from django.utils.encoding import force_unicode
 
+
 class Small(object):
     """
     A simple class to show that non-trivial Python objects can be used as